It was narrated that 'Uqbah bin 'Amir said:
"I heard the Messenger of Allah (ﷺ) say: 'The Muslim is the brother of another Muslim, and it is not permissible for a Muslim to sell his brother goods in which there is a defect, without pointing that out to him."' (FR)
English reference (FR): Vol. 3, Book 12, Hadith 2246 (FR)
Arabic reference (FR): Book 12, Hadith 2331 (FR)